Speech intelligibility testing of rail transit vehicle passenger information systems

摘要

There is increasing industry awareness of the important role speech intelligibility plays in the experience of passengers on rail transit systems. We review applicable standards and guidelines for vehicle public address (PA) systems and present an evaluation of speech intelligibility measurements of an on-board passenger information system tested during vehicle refurbishment. Tests were conducted using a mouth simulator sound source. We examine the effect of background noise due to the vehicle HVAC system on the speech intelligibility of the PA system and present an evaluation of loudspeaker performance for conformance with industry standards and the achievement of necessary speech intelligibility for passengers using the Speech Transmission Index rating.